Means for sharpening the blade of a jointer or planer

ABSTRACT

Apparatus for sharpening the blade of a jointer or planer without removing the blade, including a fixture having a track which is positioned on the bed of the jointer or planer and is aligned with the blade, and a spinning stone engaging the blade of the jointer or planer and supported on a member which rides the track, to sharpen the blade by sweeping the spinning stone along the blade.

United States Patent 1151 3,683,564 Lawrence [4 1 .Aug. 15, 1972 [54] MEANS FOR SHARPENING THE 2,944,376 7/1960 Buttke ..51/249 BLADE OF A JOINTER OR PLANER 2,620,606 12/1952 Dvorak ..5 1/249 2 I ent E. Lawrence 21 7 w t 1,834,972 SKHCX'SU'OITI 1 Ave" laarysvme, can}. 95901 3,126,675 3/1964 McEwan ..51/48 HE [221 Filed Aug 13 1970 856,726 6/1907 Ross ..51/249 21 Appl. No.2 63,575 Primary ExaminerDonald G. Kelly Attorney-Mark Mohler, Dirks B. Foster, Bruce W. I U s 51/249 Schwab and Thomas E. Ciotti [51] Int. Cl. ..BZ4b 3/38 58 Field 61 Search ..51/247, 246, 249, 31, 34 R, [57] ABSTRACT 51/34 173 Apparatus for sharpening the blade of a jointer or planer without removing the blade, including a fixture 1 Referellm Cmd having a track which is positioned on the bed of the UNITED STATES PATENTS jointer or planer and is aligned with the blade, and a spmmng stone engaging the blade of the omter or 1,085,876 2/ 1914 Redden "51/58 plane and upported on a member 'which rides the track,atlo shaflrlpeil :8 blade by sweeping the spmmng tone on e a e 2,729,923 1/1956 Durst ..51/249 1 1,074,739 10/1913 Pixley ..51/249 1 Claim, 7 Drawing Figures Patented Aug. 15, 1972 2 Sheets-Sheet 1 INVENTOR SHELDON E. LAWRENCE MX .M

ATTORNEY Patented Aug. 15, 1972 2 Sheets-Sheet 2 l NV E NTOR SHELDON E. LAWRENCE iqu d (X ATTORNEY MEANS FOR SHARPENING THE BLADE OF A JOINTER OR PLANER BRIEF SUMMARY OF THE INVENTION To sharpen the blade of, for example, a jointer, the jaws of the jointer are first opened, and the fixture of this invention is positioned directly over the blade of the jointer.

The fixture has a pair of substantially parallel spacedapart rails, each of which is positioned upon the bed adjacent a different jaw of the jointer so that the fixture is positioned over the blade of the jointer. A feeler gauge and stop depends from the fixture, engaging the blade of the jointer and against which the blade is held during sharpening. The side rails of the fixture are clamped by individually adjustable clamps to the jaws of the jointer to immobilize the fixture. I

The fixture is centered over the blade of the jointer by using a centering guide which rides on the side rails of the fixture and on the shaft of the jointer rotor, the fixture is immobilized in its correct position by adjusting the holding clamps. By individually adjusting the clamps, the fixture is centered between the side rails of the fixtures and over the rotor of the jointer in the position directed by the centering guide.

The fixture is aligned with the blade of the rotor by using an alignment guide which rides on the side rails of the fixture and contacts the blade of the jointer. The side rails are aligned with the blade by adjusting the holding clamps to cause the alignment guide to contact the blade of the jointer as the guide is swept along the rails.

A spinning grinding or sharpeningstone rides along the rails, guided by the rails to be centered over the blade of the rotor of the jointer, and tilted slightly to cause the stone to contact the blade at only the outer edge of the spinning stone. Typically, the spinning stone is positioned in the chuck of a conventional router which is attached at a predetermined angle and position to a second fixture which rides the rails of the first fixture. The vertical adjustment of the router then gives a vertical adjustment to the sharpening stone. The high speed of the router, and hence of the stone, (on the order of 20,000 rpm), facilitates the grinding of the jointer blade in that the blade may be swept rapidly by the stone.

It is therefore an object of this invention to provide a device for use on jointers, planer, and the like far more quickly and accurately sharpening the blades than heretofore.

Another object of the invention is an improved construction in a sharpening device for sharpening the cutting blades on jointers and the like in which the several cutting blades on a conventional cutting head, may be quickly sharpened without removing the blades or cutting head from the jointer and without locking and unlocking the blades during and after sharpening each blade, and without altering the sharpening device.

SHORT DESCRIPTION OF THE DRAWINGS Other objects will become apparent from the following description, taken in connection with the accompanying drawings, in which:

FIG. 1 is a view, partly fragmented, of a first embodiment of this invention, taken from above, and overlying a jointer or planar rotor;

FIG. 2 is a view, partly in section, taken at 2-2 in FIG. 1;

FIG. 3 is a view, partly in section, taken at 3--3 in FIG. 2;

FIG. 4 is a view, partly in section, showing a rotor blade positioning gauge and stop attached to the stationary portion of the fixture of this invention;

FIG. 5 is a view, partly in section, taken at 5-5 in FIG. 1, showing the centering guide riding on the side rails of the fixture of this invention, properly engaging the shaft of the jointer or planer;

FIG. 6 is a view, partly in section, taken at 6-6 in FIG. 1, showing the alignment guide riding on the side rails of the fixture and properly engaging the blade of the jointer or planar; and

FIG. 7 is a view, partly in section, of a typical grinding stone used with this invention.

DETAILED DESCRIPTION OF THE INVENTION A typical jointer or planer has a bed 10 for supporting a piece of wood which is to be planed or joined. The major difference, for purposes of this application, between a planer and a jointer is the size of the machine and the length of the blade. The rotor 18 of the jointer or planer is generally cylindrical, with at least one cutting blade positioned on the rotor to engage the wood when the wood is moved over the blade; there normally being a plurality of cutting blades equally spaced around the rotor, or cutting head, each removably secured on the head.

In stationary jointers the blade is usually, if not always straight. In some small portable jointers the blade is spiralled. The primary use of the fixture of this inven tion is for sharpening blade in stationary apparatus, but it is not limited to sharpening a straight blade. The apparatus, as explainedherein, may be used to sharpen a spiralled blade, when such blade is used, without removing blade from the jointer or planer.

Hereinafter only the word jointer will be used to describe jointers, planers, jointer-planers, and like apparatus whose blade is adapted to be sharpened by the mechanism of this invention.

The bed of the jointer has two spaced-apart portions, providing horizontally disposed, spaced, coplanar work supporting surfaces between which the rotor 18 is positioned. At least one of the portions is movable with respect to the other portion. Usually the rotor or cutting head 18 is stationary and both jaws 14 and 16 or the two portions move simultaneously toward and away from the rotor 18. The adjustment for the two jaws 14 and 16 is not shown, but is well known in the art.

A blade 20 of the jointer is embedded in the rotor 18, it being understood that a plurality of blades are used in an arrangement substantially as disclosed in U.S. Letters Patent No. 3,354,589 of Nov. 28, 1967. Typically the blade 20 fits into a slot 22 in the rotor, and it has a back up plate 24 and adjustment screws 26 for holding in the blade and adjusting its position.

In normal operation the jointer has a motor (not shown) which spins the shaft 12 and rotor 18 of the jointer, intercepting and cutting wood (not shown) with the blade 20.

The fixture apparatus of this invention has a fixed member 28 with a pair of side rails 30 and 32. The rails 30 and 32 are attached together by a pair of end brackets 34 and 36 which space them apart in substantially parallel configuration. Four clamps 38,40,42, and 44, each adapted to grasp an edge of the jaws 14 or 16, are screwed into and adjustable on the side rails 30 and 32 to position the fixed member 28 and to align it relative to the rotor 18. Adjustment of the butterfly nuts 46,48,50, and 52 aligns and centers the rails 30 and 32 over the blade 20. Movement of the jaws 14 and 16 toward each other also tightens the clamps.

A movable carrier 54 is adapted to ride the side rails 30 and 32 and to carry the sharpening apparatus during sharpening of the jointer. Grooves 56 and 57 conform to and are adapted to ride on the side rails 30 and 32. The grooves 56 and 57 are formed in a plate 58 having a large clearance hole 60 formed in the center thereof. A conventional router or other similar mechanism 62 carries a spinning shank 64 upon the end of which is a spinning grind stone 66. The router 62 has an attaching or coupling plate 68 which is typically attached by screws 70 and 72 to the plate 58. An upstanding member 74 is positioned on, and may be integral with, the plate 58 to cause the shaft of the router 62, and hence the grinding stone 66 to be tilted slightly, whereby only the edge of the spinning stone 66 contacts the blade 20 of the jointer. The tilt is exaggerated in the figures.

Because of the relatively high speed of the router, typically on the order of 20,000 revolutions per minute, the movable carrier member 54 is allowed to be swept along the tracks 30 and 32 at a rapid pace during sharpening of blade 20.

In one embodiment of the invention, a feeler gauge and stop 76 is attached to the plate 58 of the carrier 54, depending downward to slidably engage the blade 20 during sharpening of the blade.

In a second embodiment, the feeler gauge 78 (FIG. 4) is attached to one of the side rails 32 and engages blade 20. To provide resiliency in the feeler gauge, it may be rocked against a spring 80 which biases the feeler 78 against a stop 82.

Up and down adjustment of the spinning grinder 66 is effected by large threads on the router 62, whereby the the inner case 84 of the router 62 is allowed to be moved up and down (and hence the grinder 66 to be moved up and down) by turning the inner case 84 of the router relative to the outer case 86. Spinning of the shaft 64 and grinder 66 is by, e.g., electric motor of the router (not shown).

Adjustment cards for centering and aligning of the fixture fixed member 28 over and with the blade 20 are shown at 88 and 90 in FIGS. 1, and 6.

To sharpen a straight blade of a jointer 10, the method of this invention is to hold the blade of the jointer still, and precisely to move a spinning grinding stone 66 along the length of the blade 20, said precise movement being at a precise angle relative to the blade 20 to create predetermined contours of the blade 20.

More particularly, one positions a grinding member 66 at a precise position over the blade 20. One then aligns the grinding member at a precise position over the blade 20. The grinding member 66 is then aligned with the blade 20. The depth of cut of the grinding member 66 is then adjusted. The grinding member 66 is next started spinning, and the spinning member 66 is then swept the length of the blade 20, thereby sharpening blade 20.

In operation, the frame 28 is first positioned over the blade 20. The butterfly nuts 46,48,50,52 are loosened sufiiciently that the clamps 38,40,42,44 can slip over the jaws 14 and 16 of the jointer. To that end the 5 jointer jaws are preferably opened apart from their normal operating position adjacent the rotor 18. The guide 88 is next placed on the side rails 30 and 32 and over the shaft 12 of the rotor 18, thereby positioning the frame 28. The alignment of the rails 30 and 32 is initially by eye substantially parallel with the axis of the shaft 12. The butterfly nuts 38,40,42,44 are then partly adjusted to hold the frame 28 in its centered position. The jaws l4 and 16 may also be moved toward each other to tighten the clamps. The guide 90 is next positioned on the rails 30 and 32. The rotor is manually turned until the blade 20 contacts the guide 90, as

shown in FIG. 6, at one end of the blade 20. The guide is then moved along the blade 20 while the rotor is held stationary, thus causing the rails 30 and 32 to become precisely aligned with the blade 20. The clamps 38,40,42,44 are tightened and loosened to accommodate the corrected position of the member 28.

As seen in FIG. 1, the feeler gauge 76 and sharpening member 66 are positioned outwardly of one end of blade 20 when plate 58 is at one end of its movement. When router 62 is secured on plate 58 with its shank 64 centered in opening 60, and plate 58 is moved to the right from the position shown in FIG. 1, the feeler gauge 76 will be carried to a position for engagement with a side of the blade 20 as seen in FIG. 2 before the lowered trailing edge of the tilted member 66 engages the blade. In this position the feeler gauge functions as a stop against which the blade 20 is adapted to be manually held after the router is started and during movement of the carriage for carrying member 66 and the feeler 76 along the blade from one end thereof to and past the other end with the member 66 in sharpening engagement with the blade. Also the direction of rotation of the sharpening member 66 is such that it urges the blade 20 against the member 76 during sharpening of the blade.

After completing the sharpening movement of the sharpening member 66 and stop 76 to the right from the position shown in FIG. 1, the cutting head may readily be manually rotated for return of the plate 68 back to the position shown in Fig. preparatory to repositioning the stop or feeler 76, and the next blade on the head 18 for repeating the sharpening step.

If the blade 20 were spiralled, the rails would be aligned with the rotor and with the feeler gauge embodiment shown in FIGS. 1 and 2. The feeler gauge 76 would have ends which are more rounded than shown. The rails 30 and 32 would need to be aligned substantially with the axis of the shaft 12. This could be accomplished by drawing a mark (not shown) on the rotor 18 parallel to the axis of the rotor 18 and shaft 12. The gauge 90 during the alignment would then be caused to track that line instead of tracking the blade 20. During sharpening of the spiralled blade, the gauge 76 would hold the blade 20 in proper position relative to the stone 66. As the stone 66 and the gauge 76 traveled parallel to the rails 30 and 32, the rotor 18 would be slowly turned by the gauge 76 to cause proper grinding of the blade 20.

From the foregoing it is seen that the base portion of the device comprising the rigidly connected rails 30, 32

is adapted to be quickly mounted on the two portions 14, 16 of bed in a position for supporting the carrier or carriage 54in a position extending across the cutter head 18 with the router and sharpening stone 66 aligned over the uppermost blade 20 on the cutter head, and the router and stone 66 will be rigidly held in a properly tilted position so that only one edge of the circular lower face of the stone engages the blade. This rigid mounting of the router precludes any chatter in the stone or lack of precise uniformity in the sharpening of the blades.

The feeler gauge 76 functions as a movable guide means as well as a positioning means that moves with the sharpening stone 66 slidably engaging the side of the blade adjacent to the sharpening stone during movement of the sharpening stone from one end of the blade 20 to the other.

The cutting head 18 is easily manually held in a position with the uppermost blade 20 against feeler or guide element 76 during sharpening of the blade, and its position positively fixed relative to the sharpening stone at all times, once the device is secured on the bed of the jointer in the proper operative position relative to the cutting head, as herein described. There is no locking or unlocking of the blade 20 or release or readjusting of the guide element 76 relative to the blades on a cutting head after the device is in said operative position.

Although the invention has been described in detail above, it is not intended that the invention should be limited by that description, but only in accordance with the spirit and scope of the appended claims.

I claim:

1. A device for sharpening the cutter blades on and extending longitudinally of a horizontally elongated rotary cutting head of a wood working machine having a pair of spaced, horizontally disposed bed portions provided with coplanar work supporting surfaces and parallel terminal edges defining the opposite sides of the space between said portions with said cutting head extending longitudinally of said edges and fixedly journalled for moving the blades thereon upwardly, in succession, to an elevated position spaced between said edges upon rotating said cutting head,

a. a pair of rigidly connected, horizontally extending,

parallel rails spaced apart in side by side relation adapted to be supported on said bed portions in a position parallel with said cutting head with one rail of the pair along each of said edges;

b. a carriage extending between said pair of rails slidably supported thereon for reciprocable movement longitudinally of said rails from one of the ends of said cutting head to the other and vice versa when said rails and carriage are in sharpening position relative to said cutting head, and interengaging guide means respectively on said rails and carriage for holding said carriage in a path parallel with said rails during said movement;

c. said carriage being formed with a router support rigid therewith for fixedly supporting a conventional router thereon, including a motor chuck, shank and annular sharpening stone in an operative axial alignment on an axis inclined slightly relative to vertical and with said stone depending from said chuck and tilted slightly relative to horizontal. for engagement along its owered edge with the cutting edge of the uppermost blade on said cutting head when said rails and carriage are in said sharpening position, and a router including a shank and stone rigidly secured on said carriage in said operative position;

d. blade engaging means on said carriage for slidably engaging a side of the uppermost blade on said cutting head closely adjacent the stone when said rails and carriage are in said sharpening position and when said sharpening stone is in sharpening engagement with the cutting edge of such uppermost blade, and movable with said carriage longitudinally of said blade for positioning said blade and stone in a uniform position relative to each other during sharpening of said blade;

e. said rails supporting said carriage for movement of said stone and blade engaging means to positions spaced outwardly of the ends of such uppermost blade whereby said cutting head will be free to be rotated for movement of the next successive blade on said cutting head to an uppermost position for sharpening and for engagement by said blade engaging means, and means for releasably securing said rails on said bed portion with said rails and carriage in said operative position. 

1. A device for sharpening the cutter blades on and extending longitudinally of a horizontally elongated rotary cutting head of a wood working machine having a pair of spaced, horizontally disposed bed portions provided with coplanar work supporting surfaces and parallel terminal edges defining the opposite sides of the space between said portions with said cutting head extending longitudinally of said edges and fixedly journalled for moving the blades thereon upwardly, in succession, to an elevated position spaced between said edges upon rotating said cutting head, a. a pair of rigidly connected, horizontally extending, parallel rails spaced apart in side by side relation adapted to be supported on said bed portions in a position parallel with said cutting head with one rail of the pair along each of said edges; b. a carriage extending between said pair of rails slidably supported thereon for reciprocable movement longitudinally of said rails from one of the ends of said cutting head to the other and vice versa when said rails and carriage are in sharpening position relative to said cutting head, and interengaging guide means respectively on said rails and carriage for holding said carriage in a path parallel with said rails during said movement; c. said carriage being formed with a router support rigid therewith for fixedly supporting a conventional router thereon, including a motor chuck, shank and annular sharpening stone in an operative axial alignment on an axis inclined slightly relative to vertical and with said stone depending from said chuck and tilted slightly relative to horizontal for engagement along its lowered edge with the cutting edge of the uppermost blade on said cutting head when said rails and carriage are in said sharpening position, and a router including a shank and stone rigidly secured on said carriage in said operative position; d. blade engaging means on said carriage for slidably engaging a side of the uppermost blade on said cutting head closely adjacent the stone when said rails and carriage are in said sharpening position and when said sharpening stone is in sharpening engagement with the cutting edge of such uppermost blade, and movable with said carriage longitudinally of said blade for positioning said blade and stone in a uniform position relative to each other during sharpening of said blade; e. said rails supporting said carriage for movement of said stone and blade engaging means to positions spaced outwardly of the ends of such uppermost blade whereby said cutting head will be free to be rotated for movement of the next successive blade on said cutting head to an uppermost position for sharpening and for engagement by said blade engaging means, and means for releasably securing said rails on said bed portion with said rails and carriage in said operative position. 